问题

The book was written in 1946, _______ the education system has witnessed great changes.

A:since then
B:when
C:since when
D:during which

正确答案是：

同类题型

What an________movie! —Yes, all of the children were ________ in it.

____________ piece of news! Fun parks will be free until the end of this month.

_____ some people regard as a drawback is seen as a plus by many others.

He eats __________ every day. He is healthy.

You cwhere the air is thin.